i am trying to
graph the results of a survey, where
the question is multiple choice.
eg. How would you describe this website?
format:
option | number of times selected | percentage of users who selected that option
Informative 1 50%
All of
the above 1 50%
Interesting 0 0%
Intelligent 0 0%
Cool 0 0%
Incredible 0 0%
Sleek 0 0%
Amazing
the graph is a bar
graph, where each bar represents one of those options, and
the height of
the bar depends on
the number of times selected.
however,
the labels are slanted at a 45 degree angle and are barely readable! here is my code:
<?php
require_once ("includes/common.php");
require_once ("graph/mtChart.min.php");
// type must be specified
$type = $_GET['type'];
if($type == "surveys_report_MC_or_CB") {
// PARAMS
$surveyID = $_GET['surveyID'];
$questionID = $_GET['questionID'];
// END PARAMS
$question = SurveyQuestions::getSingle($questionID);
$answers = SurveyAnswers::getAll($questionID);
$options = SurveyQuestionOptions::getAll($question[SurveyQuestions::surveyQuestionID]);
$others = SurveyAnswers::setOptionCounts($options, $answers);
$printedOthers = false;
// set
graph
$values = array();
$axisLabels = array();
foreach($options as $option) {
$values[$option[SurveyQuestionOptions::optionText]] = $option['count'];
$axisLabels[] = $option[SurveyQuestionOptions::optionText];
}
$graphs = array();
$graphs[0] = $values;
$xName = "Option";
$yName = "Number of Times Selected";
$graphTitle = $question[SurveyQuestions::question];
$series = array("Total");
$showLegend = false;
$tall = false;
}
drawGraph($graphs, $axisLabels, $xName, $yName, $graphTitle, $series, $showLegend, $tall);
function drawGraph($graphs, $axisLabels, $xName, $yName, $graphTitle, $series, $showLegend, $tall) {
$Graph = ($tall) ? new mtChart(575,375) : new mtChart(575,275);
// Dataset definition
$avg = 0;
$i = 0;
foreach ($graphs as $key => $value) {
$Graph->AddPoint($value,"series" . $key);
$Graph->SetSerieName($series[$key],"series" . $key);
// Get average
$avg += array_sum($value);
$size = sizeof($value);
$i += $size;
// Calculate x-axis tick interval
$step = ceil($size / 25);
}
$Graph->AddPoint($axisLabels,"XLabel");
$Graph->AddAllSeries();
$Graph->RemoveSerie("XLabel");
$Graph->SetAbsciseLabelSerie("XLabel");
$Graph->SetXAxisName($xName);
$Graph->SetYAxisName($yName);
// Get from cache if it exists
$Graph->enableCaching(NULL, 'graph/cache/');
$Graph->GetFromCache();
// Initialize
the graph
$Graph->setInterval($step);
$Graph->setFontProperties("graph/tahoma.ttf",8);
($showLegend) ? $Graph->setGraphArea(45,30,475,200) : $Graph->setGraphArea(75,30,505,200);
$Graph->drawGraphArea(255,255,255,TRUE);
$Graph->drawScale(SCALE_START0,100,100,100,TRUE,55,1,TRUE);
$Graph->drawGrid(4,TRUE,230,230,230,50);
// Draw
the 0 line
$Graph->setFontProperties("graph/tahoma.ttf",6);
$Graph->drawTreshold(0,143,55,72,TRUE,TRUE);
// Draw
the bar
graph
$Graph->drawBarGraph();
// Draw average line
$Graph->drawTreshold($avg/$i, 0, 0, 0, FALSE, FALSE, 5);
// Finish
the graph
$Graph->setFontProperties("graph/tahoma.ttf",8);
if ($showLegend) {
$Graph->drawLegend(482,30,255,255,255,255,255,255,100,100,100);
}
$Graph->setFontProperties("graph/tahoma.ttf",10);
$Graph->drawTitle(0,22,$graphTitle,100,100,100,555);
// Draw
Graph
$Graph->Stroke();
}
and here is where i use it on
the page:
<div class="graph_container">
<img src="drawGraph.php?type=surveys_report_MC_or_CB&surveyID=<?php
echo $survey[Surveys::surveyID] ?>&questionID=<?php
echo $question[SurveyQuestions::surveyQuestionID] ?>" />
is there a setting i can apply to
the graph which will make
the text look nicer, or at least let me set
the angle to 90 degrees so people can read it if they cock their head to
the left?
thanks!
btw, mtchart is located here: http://code.google.com/p/mtchart/
and pchart (the original, which has mainly
the same code) is here: http://pchart.sourceforge.net/documentation.php
